Progressive encephalomyelitis with rigidity and myoclonus: a case report / 中华神经科杂志

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a specific subtype of the stiff-person syndrome, which is rare and difficult to diagnose clinically. A case of PERM in a 66-year-old female with a fluctuating progressive course was reported in this article. She had increased facial muscle tone, pruritus and sensory hypersensitivity mainly in the head and neck, medullary involvement syndrome and bilateral lower limb rigidity as the main clinical manifestations, and a previous history of pulmonary malignancy, thymoma, typeⅠ diabetes and Hashimoto′s thyroiditis. The patient′s serum and cerebrospinal fluid were positive for anti-glutamic acid decarboxylase antibody. The electromyogram showed a large number of motor unit potentials in the trunk and proximal extremities in the quiet state, which were significantly enhanced during spastic episodes, consistent with the electromyographic manifestations of stiff-person syndrome. The final diagnosis was PERM, and immunotherapy including gamma globulin and hormone responded well. PERM is a rare neurological autoimmune disease with atypical early symptoms, which can be easily misdiagnosed, and it requires attention to avoid delaying the diagnosis.

Current researches of the role of dural immunity in neuroinfectious and neuroimmune diseases / 中华神经科杂志

Dura mater, rich in vasculature and immune cells, is the outermost layer of the central nervous system, and thus acts as the first barrier to protect brain. Meningeal lymphatic vessels and immune cells are main components of dural immunity, which respond to a variety of central nervous system diseases. Meanwhile, compared with brain parenchyma, dura mater communicates more with peripheral tissues and is more susceptible to medical interventions. Therefore, dura mater is a promising target to prevent, diagnose and treat intracranial diseases. Here dural immunity is clarified based on meningeal lymphatic vessels and dural immune cells, and current researches inquiring the role of dural immunity in infectious and immune diseases of central nervous system are summarized.

Clinical application of Fastpass Scorpion suture passer for arthroscopic Bankart repair / 中国修复重建外科杂志

OBJECTIVE@#To explore the effectiveness and advantages of using Fastpass Scorpion suture passer to stitch the inferior capsulolabral complex in arthroscopic Bankart repair compared with traditional arthroscopic suture shuttle.@*METHODS@#The clinical data of 41 patients with Bankart lesion, who met the selection criteria and were admitted between August 2019 and October 2021, was retrospectively analyzed. Under arthroscopy, the inferior capsulolabral complex was stitched with Fastpass Scorpion suture passer in 27 patients (FS group) and with arthroscopic suture shuttle in 14 patients (ASS group). There was no significant difference between the two groups ( P>0.05) in gender, age, injured side, frequency of shoulder dislocation, time from first dislocation to operation, and preoperative Rowe score of shoulder. Taking successful suture and pull-tightening as the criteria for completion of repair, the number of patients that were repaired at 5∶00 to 6∶00 (<6:00) and 6∶00 to 7∶00 positions of the glenoid in the two groups was compared. The operation time, and the difference of Rowe shoulder score betwee pre- and post-operation, the occurrence of shoulder joint dislocation, the results of apprehension test, and the constituent ratio of recovery to the pre-injury movement level between the two groups at 1 year after operation.@*RESULTS@#Both groups completed the repair at 5∶00 to 6∶00 (<6∶00), and the constituent ratio of patients completed at 6∶00 to 7∶00 was significantly greater in the FS group than in the ASS group ( P<0.05). The operation time was significantly shorter in the FS group than in the ASS group ( P<0.05). All incisions in the two groups healed by first intention. All patients were followed up 12-36 months (mean, 19.1 months). No anchor displacement or neurovascular injury occurred during follow-up. Rowe score of shoulder in the two groups significantly improved at 1 year after operation than preoperative scores ( P<0.05), and there was no significant difference in the difference of Rowe shoulder score between pre- and post-operation between the two groups ( P>0.05). At 1 year after operation, no re-dislocation occurred, and there was no significant difference in the apprehension test and the constituent ratio of recovery to the pre-injury movement level between the two groups ( P>0.05).@*CONCLUSION@#Compared with the arthroscopic suture shuttle, using Fastpass Scorpion suture passer to stitch the inferior capsulolabral complex in arthroscopic Bankart repair is more convenient, saves operation time, and has good effectiveness.

A double-blind randomized controlled trial on the efficacy of mixed pure tone sound therapy in chronic tinnitus patients with different hearing loss / 中华耳鼻咽喉头颈外科杂志

Objective@#The effectiveness of two different sound therapies in chronic subjective tinnitus was compared. The effectiveness of different degrees of hearing loss patients on two different sound therapies were analyzed preliminarily and the possible mechanisms were discussed.@*Methods@#This clinical trial was conducted in the Peking Union Medical College Hospital, China from January 2018 to April 2018. Patients were received sound therapy when they were diagnosed as subjective tinnitus. This was a double-blinded randomized controlled trial. In our clinical trial, we included 56 participants who were randomly divided into Groups A and B with different sound therapies by using a computer allocation sequence. Pure tone audiometry, tympanometry and tinnitus matching were performed. The patients were followed up for 2 weeks, 1 month, 2 months and 3 months. Tinnitus handicap inventory (THI) and visual analog scales (VAS) measuring were used to evaluate the handicap, loudness and anxiety of tinnitus. An analysis of variance (ANOVA) of 2×5 repeated-measures was conducted.@*Results@#With the prolongation of the treatment time, both groups showed significantly lower scores after 3 months training compared with baseline which were measured by THI scores. While there was no effect between the two groups. According to the degree of hearing loss, Group A and B were divided into normal to mild hearing loss group (26-40 dB HL, Group A1, Group B1), moderate to profound hearing loss group (41 dB HL group and above, Group A2, Group B2). In the patients with normal hearing and mild hearing loss, the THI (P=0.013), VAS loudness and annoyance scores (P<0.01) after 3 months in Group B1 was significantly lower than those at baseline and the sound therapy in Group B1 was effective. In patients with moderate to profound hearing loss, the THI, VAS loudness and annoyance scores (P<0.01) after 3 months in Group A2 was significantly lower than those at baseline and the sound therapy in Group A2 was effective.@*Conclusions@#Sound therapy may be effective for some patients. Sound therapy for patients with different degrees of hearing loss are different. The tinnitus of most patients could not disappear completely, but reduce or eliminate. Doctors should use appropriate and individualized acoustic parameters for different characteristics of tinnitus. Doing so would provide effective and specific sound therapy for patients and reduce or eliminate tinnitus.

Advances of chronic tympanic membrane perforation animal model / 中华耳鼻咽喉头颈外科杂志

Chronic tympanic membrane perforation in an animal model has been widely used. The ideal model is a lasting and stable perforation without infection. For half a century, several physical modalities have been evolved, such as thermal injury, infolding technique, tympanostomy tube, re-myringotomy, and laser myringotomy. Chemical methods using chemical substance inhibiting growth and repair of cells as well as using gene defect animals are also applied. We have found the success rate is lower when using only one method and it would be better to combine physical and chemical approaches. In this article, we review the research advances in the establishment of chronic tympanic membrane perforation animal model.

The advance of materials for preventing adhesion in tympanoplasty / 中华耳鼻咽喉头颈外科杂志

For otitis media patients with severe mucosal lesions, adhesion is the most common poor prognosis of tympanoplasty. We generally consider tympanic cavity adhesion is due to eustachian tube dysfunction and poor middle ear ventilation. The mechanism of adhesion is unclear so far, which we thought is mainly associated with wounded surface and activation of the fibrinolytic system. To solve the problem of adhesion, several materials have been used in the middle ear surgery, such as plastic sheet, silicone sheet and absorbable material. And there are some benefits. The most widely used is silicone sheet, and there are some researches focused on its thickness, shape and components to achieve better anti-adhesion effect. In this article, we will do a review for the research advances of anti-adhesion materials in tympanoplasty.

The effects of static progressive stretching combined with joint mobilization on dysfunction after total knee arthroplasty / 中华物理医学与康复杂志

Objective To explore the effect of static progressive stretching combined with joint mobilization on dysfunction after total knee arthroplasty.Methods Fifty-six patients with knee joint dysfunction after total knee arthroplasty were randomly divided into a treatment group and a control group,each of 28.Both groups were treated with joint mobilization,while the treatment group was additionally provided with static progressive stretching for 8 weeks.Before and after the treatment,both groups' pain and knee function were evaluated using visual analogue scale (VAS) scores,the range of motion and the hospital for special surgery knee score (HSS).Results Before the treatment there were no significant differences between the two groups in any of the measurements.After the treatment,all of the measurements had improved in both groups,on average.Compared with the control group,the treatment group's average range of motion of the knee and HSS score were significantly better.Conclusion Static progressive stretches combined with joint mobilization can effectively relieve pain,expand the range of motion and improve the function of a knee joint after total knee arthroplasty.

The evaluation of Xpert MTB/RIF for the diagnosis of tuberculous meningitis / 中华检验医学杂志

Objective To evaluate the diagnostic performance of Xpert MTB/RIF for the diagnosis of tuberculous meningitis (TBM).Methods This was a prospective, single center clinical trial.A total of 116 consecutive patients with suspected meningitis who were admitted to Xijing Hospital from October 2013 to June 2015 were recruited.Mycobacterium tuberculosis ( MTB) and rifampicin ( RIF) resistance mutations in 1 ml cerebrospinal fluid ( CSF) were detected with Xpert MTB/RIF and the remaining sample was tested by Ziehl-Neelsen staining , MGIT960 liquid culture and other laboratory tests .And the enrolled patients were grouped according to the 2010 South African expert consensus .The diagnostic performance of Xpert MTB/RIF was evaluated by comparing against clinical score >5 points and MGIT960 liquid culture as reference standards respectively .The comparison was performed using a χ2 test or Fisher′s exact test for categorical variables and a nonparametric rank sum test for continuous variables .Results Among the enrolled 116 subjects, 23 subjects were diagnosed as definite-TBM by MGIT960 liquid culture, 16 subjects were classified as probable TBM , 27 subjects were classified as possible TBM , and 50 subjects were classified as non-TBM.When clinical score >5 points was used as a reference standard , the sensitivity of Xpert MTB/RIF (39.4%) was comparable with that of MGIT960 liquid culture (34.8%) (χ2 =0.292, P=0.589), and significantly better than that of Ziehl-Neelsen staining (9.9%) (χ2 =16.500, 12.771, P<0.001). No significant differences were found among the specificities of Xpert MTB /RIF, MGIT960 liquid culture and Ziehl-Neelsen staining ( 98.0%, 100.0% vs 98.0%, χ2 =1.014, P=0.602 ) .When tested against MGIT960 liquid culture as a reference standard , the sensitivity of Xpert MTB/RIF was 91.3%. Conclusions Xpert MTB/RIF is a rapid and specific method to detect MTB and RIF resistance in CSF .It exhibits a good rule in value for the diagnosis of TBM and a comparable sensitivity with MGIT 960 liquid culture, thus it can be used as the initial method for the diagnosis of tuberculous meningitis .

Tuberculous meningitis in Asia

Tuberculous meningitis is an important global medical problem which gives rise to high morbidity and mortality. It is the most severe form of extrapulmonary Mycobacterium tuberculosis. Comprehensive prevention effort, prompt diagnosis and rational treatment are all keys to improving treatment outcomes; yet many unsolved problems remain. On the other hand, the new problems, such as HIV co-infection and drug-resistance are posing important challenges. This review outlines the epidemiology, pathogenesis, diagnosis, management and prognosis of tuberculous meningitis. We mainly focus on research carried out in the recent decades, giving special attention to the work done among the Asian populations

Design and Realization of Independent Calling Device for Patients with Amyotrophic Lateral Sclerosis / 中国康复理论与实践

@#Objective To design a device for the patients with amyotrophic lateral sclerosis (ALS), who are disable to speak and move, to call for the nurses independently when necessary. Methods The electroencephalographic signals were collected and processed with TGAM, and the extracted attention characteristic values were transmitted to a computer with Bluetooth. The loudspeaker would call the nurses when the attention characteristic value exceeds the normal range. Results In the testing process of 20 participants in 10 tests, the success rate was 81.5%, and the average misjudged frequence was 0.2 within 20 min. Conclusion The device can be used in the nursing of the patients with ALS to meet the needs of daily nursing work.

The killing effect of bone cement on spinal metastasis of transplanted VX2 carcinoma in experimental rabbit models / 介入放射学杂志

Objective To investigate the killing effect of polymethylmethacrylate (PMMA) on spinal metastasis of transplanted VX2 carcinoma in experimental rabbit models. Methods Spinal metastasis of transplanted VX2 carcinoma model was successfully established in 18 rabbits. The experimental rabbits were randomly and equally divided into three groups with 6 rabbits in each group. Under CT guidance , PMMA or saline was injected into the center of VX2 tumor; in group A 0.3 ml of PMMA was used, in group B 0.1 ml of PMMA was used and in group C (control group) 0.3 ml saline was used. Twenty-four hours after the injection, the animals were sacrificed. Four tissue samples were obtained from the sites at 1 mm , 5 mm, 10 mm and 15 mm away from the PMMA mass in each rabbit of group A and group B , while four tissue samples were collected from different four sites from the tumor ’s center to border in each rabbit of group C. TdT-mediated dUTP nick-end labeling (TUNEL) method was used to determine the tumor cell apoptosis rate. Results After successful establishment of rabbit model, injection of PMMA was performed in sixteen among the eighteen rabbits. Technical success rates were 83.3% in both group A and B, and the success rate was 100% in group C. The difference in technical success rate was not significant. The mean tumor cell apoptosis rates of spinal VX2 carcinoma at 1 mm, 5 mm and 10 mm away from the PMMA mass in group A were (65.75±18.81)%, (50.00±14.24)% and(14.95±8.98)% respectively. The mean apoptosis rate in the control group was (9.79 ±5.24)%; the differences between the group A and the control group were statistically significant (P<0.05). The mean tumor cell apoptosis rate of spinal VX2 carcinoma at 15 mm away from the PMMA mass in group A was (10.30 ±8.13)%, which was not significantly different with that of the control group. The mean tumor cell apoptosis rates of spinal VX2 carcinoma at 1 mm and 5 mm away from the PMMA mass in group B were (49.20±15.57)% and(17.75±9.28)% respectively, which was significantly different with that of the control group(P<0.05); the mean tumor cell apoptosis rates at 10 mm and 15 mm away from the PMMA mass in group B were not significantly different with those of the control group. Statistically significant differences in the mean tumor cell apoptosis rates determined at 1 mm, 5 mm and 10 mm away from the PMMA mass existed between group A and group B(P<0.001). Conclusion PMMA can promote the apoptosis of tumor cells, properly increasing the injected amount of PMMA can enlarge the extent of tumor cell apoptosis.

Blink restoration by the functional electrical stimulation in unilateral facial nerve palsy rabbits / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>Tocompare the effects of different waveforms and parameters of electrical stimulation to elicit a blink, and construct a functional electrical stimulation (FES) system to restore synchronous blink in unilateral facial nerve palsy (FNP).</p><p><b>METHODS</b>Firstly, twenty-four rabbits were surgically induced unilateral FNP and were divided into three groups, who received square, sine and triangle pulse wareforms, respectirely. Both the healthy and the paralysis eyelids of the rabbits received pulse train stimulation to produce a blink in both eyes. For each rabbit, twenty-seven combinations of frequencies (25 Hz, 50 Hz and 100 Hz) and nine pulse widths (1-9 ms) were stimulated. The threshold amplitude and electric charge to elicit a blink was compared between different waveforms and different parameters. Secondly, a FES system was constructed to treat six surgically induced unilateral FNP rabbit chosen in the twenty-four rabbits, it consisted by an electromyogram (EMG) amplifier module which record the EMG of the healthy muscle, and a stimulator which received the EMG input and output a pulse train stimulation when triggered by the EMG.</p><p><b>RESULTS</b>When the carrier frequency of the pulse train was 25 Hz, it was not able to induce a smooth blink. However, when the carrier frequencies were 50 Hz and 100 Hz, a smooth blink could be induced. The voltage required by 100 Hz was lower than 50 Hz, but it cost more electric charge. The amplitude that square waveforms required was far lower than sine and triangle, but the electric charge between the three waveforms was similar. Synchronous blink could be restored in the six unilateral FNP rabbits with the FES system.</p><p><b>CONCLUSIONS</b>To elicit a blink, square pulse train delivered in 50 Hz is a preferable option. The motion of the healthy eyelids as a source of information for stimulation of the paralyzed sides can restore the synchronous blink in unilateral FNP rabbits.</p>

Cochlear implantation with pericanal electrode insertion technique / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To investigate the surgical technique of the pericanal electrode insertion technique for ies cochlear implantation.@*METHOD@#Forty cases of sensorineural deafness were subjected to the ies cochlear implants. Cochleostomy was performed through the external auditory canal with a microdrill anterior to the round window. The electrode impedance and electrically auditory brainstem responses(EABR) were tested during the operation. The X-ray photographs were taken after the operation. The cochlear implant was activated in all 40 cases 4 weeks following surgery.@*RESULT@#All of the electrodes were inserted and all of the implants worked well. No electrode extrusions or serious surgical complications happened during postoperative observation for 6 months.@*CONCLUSION@#The pericanal electrode insertion technique is a safe approach for ies cochlear implantation.

Expression of Toll-like receptor 4 induced by extravasated IgG and peripheral LPS in rat brains / 解剖学报

ObjectiveTo investigate the effect of immunoglobulin G (IgG) extravasated from blood circulation on the expression of toll-like receptor 4 (TLR4) induced by peripheral lipopolysaccharide (LPS) in rat brain. Methods The rats were divided into four groups in random, 5 rats in each. Group one received LPS 100μg/kg by intraperitoneal administration, normal saline was given by intravenous injection 6 hours later; group two was injected with adrenalin (AD) 15μg/kg intravenously; group three was treated with LPS intraperitoneally, AD was injected 6 hours later; group four was injected normal saline intravenously as control. For all groups, the animals were sacrificed 30 min after the last injection, and the brains were taken for investigation of the TLR4 expressions by immunofluorescence staining and RT-PCR. Result Immunofluorescence staining showed that IgG immunoreactive product was patch-like, distributed in the brain parenchyma in all the animals that received AD. In the LPS+normal saline group, IgG was found merely around the blood vessels. Meanwhile, in LPS+AD animals, TLR4 immunoreactive product coexisted with microglia marker Iba-1 within the IgG extravasated area. The double-labeled cells dispersed in the brain parenchyma and near to the cerebral vessels. In the LPS+saline group, TLR4 positive cells were endothelial-like. RT-PCR results indicated that the expression level of TLR4 in the LPS+AD group were significantly higher than that in the LPS+saline group or AD group or the saline control (P<0.01). Conclusion Extravasated circulating IgG may enhance the TLR4 expression in the rat brain induced by peripheral LPS.

Applied anatomy of the internal maxillary artery in pterygopalatine fossa under transnasal endoscopic surgery / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To explore the rules about the pathway and branch patterns of the internal maxillary artery in pterygopalatine fossa, provide the anatomic basis for treating the internal maxillary artery during the transnasal endoscopic surgery.@*METHOD@#Ten adult cadaveric skull base were dissected, the sphenopalatine artery and its branches were observed. The pterygopalatine fossa was opened through trans-maxillary sinus endoscopic approach, all the branches of the internal maxillary artery in pterygopalatine fossa were exposed. The concave of the maxillary sinus posterior-medial wall was defined as point A, the cross point of the horizontal line pass through the infraorbital foramen, the maxillary sinus anterior wall and posterior-lateral wall as point B, the cross point of the maxillary sinus anterior wall, floor and posterior-lateral wall as point D, the midpoint of BD as C, the C' denoted the first branch root of internal maxillary artery in pterygopalatine fossa. Observed the pterygopalatine segment of internal maxillary artery based on the marking points.@*RESULT@#The distance between the sphenoid sinus os and the sphenopalatine fossa was (5.88 +/- 2.21) mm. The C' point locate on AC at 13 sides specimen, locate on AB at 5 sides specimen, locate on AC at 1 side specimen, higher than AB at 1 side specimen.@*CONCLUSION@#Being familiar with the pathway and branch patterns of the internal maxillary artery in pterygopalatine fossa is important for treating the uncontrol epistaxis and endoscopic pterygopalatine fossa surgery, the rules described by A, B, C, D in our experiments will be helpful in ligation of internal maxillary artery during the endoscopic transnasal/maxillary-pterygopalatine fossa surgery.

Preliminary study on the applied anatomy data collection for the transnasal endoscopic surgery of skull base / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To explore the feasibility to measure the anatomy landmarks in the anatomy research, even in the operation by the MicronTracker binocular visual navigation system, and to study the anatomy of the transnasal endoscopic surgery of skull base.@*METHOD@#We designed a new anatomy data collection system based on the MicronTracker binocular visual navigation system to measure and record the anatomy landmarks, and measured the angles and distances between the related planes and the important structures on 67 dry adult cranium specimens (32 male, 35 female).@*RESULT@#1) The system is reliable, the angles and the distances can be acquired in the real time. 2) The major date of the landmarks was the pitch of the Frankfurt horizontal plane according to the frontal bone plane, male: (77.7 +/- 4.7) degrees, female: (81.6 +/-4.5) degrees; the pitch of the bony nasal floor according to the frontal bone plane, male: (78.6 +/- 5.8) degrees, female: (82.0 +/- 4.5) degrees; from the same side of nasal spine to the anterior edge of foramen lacerum, pitch, male: (61.3 +/- 7.6) degrees, female: (65.6 +/-7.1) degrees, azimuth, male: (7.0 +/- 2.6) degrees, female: (7.1 +/- l.8) degrees, the distance, male: (68.9 +/- 4.1) mm, female: (66.3 +/- 3.9) mm; from the same side of the nasal spine to the aperture of the sphenoidal sinus, pitch, male: (40.5 +/- 9.3) degrees, female: (46.4 +/- 6. 8) degrees, azimuth, male: (2.1 +/- 1.8) degrees, female: (3.6 +/- 2. 6) degrees, the distance, male: (56.2 +/- 3.1) mm, female: (53.4 +/- 3.0) mm.@*CONCLUSION@#1) The anatomy data collection system based on the MicronTracker binocular visual navigation system can be used to measure the anatomy landmarks conveniently, accurately and quickly. 2) The relationship between the landmarks of the skull base and the nasal cavity and the frontal bone plane and the sagittal plane is stable, and the planes can be used as the datum plane to look for the landmarks in the transnasal endoscopic surgery of skull base.

Comparative study of several methods for producing experimental animal model of viral facial palsy / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To select the optimal method for developing experimental animal model of viral facial paralysis by comparing several inoculation methods.@*METHOD@#One hundred and twenty Balb/c mice were divided into 4 groups, with each group having 30 mice. Group A, the posterior auricular branch of right facial nerve were incised and inoculated with 25 microl HSV-1; group B, 25 microl HSV-1 were inoculated into the posterior aspect of the right auricle by cutaneous scarification; group C, 25 microl HSV-1 were injected into subcutaneous tissue of the posterior aspect of the right auricle; group D, 100 microl HSV-1 were inoculated in the way similar to that of group C. The symmetry of mouse face was observed, and the incidence of paralysis and death were analyzed. The temporal bones of paralyzed mice were serially sectioned and stained with hematoxylin and eosin.@*RESULT@#Thirteen (43.33%) mice developed the right facial paralysis and recovered from it 3-7 days later in group A. Six (20%) mice developed the paralysis and recovered from it 2-9 days later in group B. Group C had no signs of facial paralysis and group D had 1 paralyzed animal. Except for 12 mice in group D, there was no death in the other groups. Nerve swelling was observed in right temporal facial nerve of paralyzed mice. Facial nerve to facial canal cross-sectional area ratio (FN/FC) of the right side was much higher than that of the left side.@*CONCLUSION@#Inoculating HSV-1 into the posterior auricular branch of facial nerve can produce an acute and transient facial paralysis in mice. With the advantage of higher morbidity of facial paralysis and lower mortality in comparison to the other methods, it is an optimal method.

A 20-year follow-up study on the effects of long-term exposure to thorium dust / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the possible effects of long-term exposure to dust containing thorium and thoron progeny on dust-exposed miners.</p><p><b>METHODS</b>A negative, high voltage, exhaled thoron progeny measurement system was used to estimate the miners' thorium lung burden.</p><p><b>RESULTS</b>The highest thorium lung burden of 638 miners was 11.11 Bq. The incidence of stage 0(+) pneumoconiosis was higher among dust-exposed miners. Lung cancer mortality of the dust-exposed miners was significantly higher than that of controls (P < 0.005).</p><p><b>CONCLUSION</b>There is a difference in cancer rates between those who have long-term exposure to dust containing thorium (in which carcinogenic ThO(2) and SiO(2) exist) and thoron progeny and those who have not.</p>